The present invention relates to wireless building automation. In particular, distance measurement is provided for locating or determining a position of a wireless building automation device.
Building automation devices are positioned throughout a building. For example, a temperature sensor or thermostat is positioned on a wall in a room and a corresponding actuator is positioned above a ceiling for controlling airflow, heating or cooling. As another example, a motion sensor is positioned on a ceiling for actuating a light controlled by a ballast balance above the ceiling. Security, fire, heating, ventilation, air conditioning (HVAC) or other networks of devices automate building control. The relative positions of different devices or the relative positions of devices with respect to the layout of a building or rooms may be used to better optimize the automation. To determine the different positions, a blueprint or map is generated of the automation system. The devices are located manually, and corresponding association tables between devices are created. Manual mapping may be inaccurate. When a device malfunctions, inaccurate mapping or no mapping makes locating a device difficult, particularly where the device is located out of site above a ceiling or in a wall. Adding visual indications identifying a location of an otherwise out of site device is unaesthetic. Manually locating devices for replacement may be time consuming and costly.